Concave objects

Hi all,

I’m attempting to draw a number of shapes from a list of vertices using GL_POLYGON. However I am getting some strange effects when the objects are concave in shape. I checked the openGL programmers guide and it seems to state that polygons have to be convex. If this is the case, how do you draw concave objects ?

Any help would be appreciated !


Divide it and create small triangle parts.Shortly make it convex.